Arc-lamp.



No. 895,594. PATENTED AUG. 11, 1908. B. A. STOWE. ARC LAMP.

APPLICATION FILED AUG. 3, 1905.

FMTM v v UNITED STATES PATENT OFFICE.

BERNARD A. STOWE, OF CLEVELAND, OHIO, ASSIGNOR TO THE JANDUS ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ARC-LAMP.

Specification of Letters Patent.

Patented Aug. 11, 1908.

Application filed August 3, 1905. Serial No. 272,488.

To all whom it may concern:

Be it known that I, BERNARD A. STOWE, a citizen of the United States, resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Imrovement in Arc-Lamps, of which the foll owing is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

My invention relates to arc-lamps of the inclosed type and particularly to the means embodied therein which are adapted to control the rate of consumption of the carbons consequent upon the fluctuations of the arc and the pumping action of the moving carbons.

It is the object of the invention to provide means which shall prolong the life of the carbons and which shall regulate and control the interchange of gases between the arcchamber and the atmosphere, so as to maintain a practically uniform mixture of gases in the arc-chamber and thus effect a steady and uniform burning at the arc.

Said invention is designed to be a modification, and an improvement in simple form, of the arc-lamp shown and described in U. S.

Letters Patent, No. 797,629, dated August 22, 1905, and consists of the means hereinafter fully described and specifically set forth in the claims.

The annexed drawing and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawing: Figure 1 represents a vertical section of an inclosed arclamp embodying my invention, taken upon the planes designated by the lines 1-1, Figs. 2 and 3, portions of the lamp out by the planes of section being shown in elevation; and Figs. 2 and 3 represent horizontal sections, taken upon the planes designated by the lines 2-2, and 33, respectively, Fig. 1.

My invention is embodied in a structure A serving as a supporting member together with several other elements hereinafter described. Said structure comprises upright body-portions a formed with a laterally-projecting upper member a and a laterally-projecting lower member (L The upper member a is secured to the floor-plate B and forms the connecting mechanical supporting medium between the center tube B and the lower portion of the lamp. Said supporting member A is insulated from the floor-plate B by means of mica-sheets a and insulated bushings c surrounding the fastening screws 0, as will be readily understood.

Suitably secured to the upper surface of the member a is a curved plate D provided with two upwardly-extending projections 61 and two laterallyextending ears (1, said plate D being insulated from the member a by means of mica-sheets a and insulated bushings c surrounding the fasteningscrews c. To the ears d are secured the rods (1 for supporting the glass globe O against the lower surface of the member a To one projection d is connected a terminal of the electrical conductor, while passing through the other projection and suitably and adjustably supported therein by means of a small screw, Fig. 2 is an elongated attentuated tube f to be hereinafter more fully described. The lower member a of the member A is pr0- vided. with a central opening a which provides a channel for receiving the positive carbon E, said channel being of a diameter substantially equal to that of said carbon so as to permit of the movement or pumping action of the latter through the same but which prevents the ready escape of the arc-gases through the same. Two shallow annular transverse chambers o intersecting the member (1 intermediate of the lower and upper surfaces of the latter, and communicating with the channel a serve as a gascheck or reservoir for such of the arc-gases as do escape from the arc-chamber through the opening a during the pumping of the carbons, and thus prevent the entrance of oxygen to the arc-chamber when the carbons again recede from each other and the gas is again drawn into the chamber.

I have provided a reservoir F into and from which the arc-gases or, more properly, the heaviest portion of the arcgases, may freely enter and withdraw during the relative movements of the carbons or during the changes of temperature in the arc-chamber, such gas-reservoir or outlet being wholly independent of the outlet a surrounding the positive carbon E.

I have found that the temperature of the gases in the inclosure is a function of the tension of the arc, and that the entrance or exit of the positive carbon does not correspondingly expel or draw in external air. On the other hand, the drop in temperature becomes so marked when the arc shortens and the voltage decreases, that the contraction of the gases exceeds in amount the increased volume of positive carbon resulting from the corresponding entrance of such carbon. The contrary is also true when the are lengthens and the voltage increases. This does not, however, affect the principle of operation of the lamp. Said reservoir F comprises an elongated attenuated tubef suitably secured at its upper end in one of the projections d and supporting at its lower end the negative carbon E which is secured thereto by means of a member G having a central recess for receiving the carbon, a pivoted support g upon which the latter rests, and a clamp g for securing the carbon in such recess. It will be noted that the lower end of said tube f thus taps the lower portion of the arcchamber and permits of the entrance and escape of the heaviest arc-gases during the relative movements of the. carbons. Removably and adjustably supported upon the upper end of the tube f and communicating therewith is a second member of the reservoir F, such member comprising a chamber 1" of enlarged cross-section provided. with an outlet of restricted cross-section communieating directly with the atmosphere. This chamber f I shall refer to as the expansion and diffusion chamber. The volume of the reservoir F is such that it will be greater than the difference between the volume of the gaseous contents of the arc-chamber at a given temperature and pressure and the volume of such gaseous contents at the same pressure and the maximum temperature imparted to it during the lamps operation.

I am aware that an outlet for the arc-gases from the arc-chamber which is independent of the upper end or outlet of the channel which forms the feed-opening for the movable electrode and which is a freer path of escape for such gases than said channel-outlet, is not new, the same being shown and described in U. S. Letters Patent No. 797,629, to which I referred above, said independent outlet comprising in said prior application, as it does in this, an elongated attenuated tube communicating directly with the arc-chain.- ber and a chamber of enlarged cross-sectional area communicating with said tube and with the atmosphere. The function of said independent outlet is, briefly, to serve a reservoir for the gases that are exhaled from the arc-chamber during the breathing of the lamp, such gases again being inhaled into the arc-chamber when the temperature within the arc-chamber falls or the carbons move farther apart, the volume of said. reservoir seasea being, as noted above, in excess of the difference between the maximum and minimum volumes of the arc-chamber, so that the oxygen of the atmosphere cannot enter the arcchamber except by diffusion through the. interposed volume of gases in the reservoir, the exclusion of the oxygen thus procuring a more economical consumption of the carbons, as will be understood. The attenuated form of the tube keeps a sufficient volume of arc-gases between the arc-clmmber and the atmosphere, and the elmmberj" acts as a diffusion chamber and also as a gas-check which prevents, by its enlarged cross-sectional area, the sudden expulsion of the arcgases into the atmos )here due to their sudden e bansion from various causes in the tubef. In this form of lamp, the gases intermediate of the lower end of the tubefand the are also act as a reservoir of gas which exercises a function similar to that of the reservoir formed by tube f, since any diffusion of oxygen from the exterior must take place through it before it reaches the combustion area. However, I have discovered that said independent outlet best subserves the general purposes above outlined, if it acts as a reservoir for the heaviest arc-gases which are more immobile than the light gases, prevents more effectually the diffusion of the oxygen, and. acts better as a cushion against sudden expansion. I have, therefore, provided an inclosure forming an arcchamber in combination with an independent outlet which taps the lower portion of the arc-chamber and serves as av reservoir for the heavy gases which will be found in that part of the chamber. I am. not aware that this independent outlet has been thus utilizcd, but only as a reservoir which taps the upper portion of the arc-clnlmber and thus receives the lightest gases, which is not as serviceable and economical as my improved construction for the reasons given above. One advantage which this improved form of lamp presents over that forming the subject-mattcr of my above-named application, arises out of the fact that any cooler gases containing oxygen entering from the exterior gain access to the interior of the inclosure at the bottom and hence, being heavier, tend to remain there and do not readily reach the combustion area, whereas in my previously constructed lamp all communieation with the exterior was had. at the upper portion of the inclosure. In the latter case the heavier exterior air when it gained access passed downwardly and thus through or in immediate proximity to the combustion area.

Having thus described my invention in detail, that which I particularly point out and distinctly claim is:

1. In an arc-lamp, the combination with an inclosure forming an arc-chamber; of a member connected therewith communicating with the atmosphere and tapping that portion of the arc-chamber that contains the heaviest gases, the end of said member communicating with the atmosphere being provided with a diliusion chamber.

2. In an arc-lamp, the combination with an inclosure forming an arc-chamber; of a member connected therewith embodying an attenuated tube and a chamber of enlarged cross-sectional area, said member communieating with the atmosphere and tapping that portion of the arc-chamber that contains the heaviest gases.

3. In an arc-lamp, the' combinationwith an inclosure forming an arc-chamber; of a member connected therewith embodying an attenuated tube tapping that portion of the arc chamber that contains the heaviest gases, and a chamber of enlarged cross-sectional area communicating with the atmosphere.

4. In an arc-lamp, the combination with an inclosure forming an arc-chamber; of a member connected therewith embodying an elongated attenuated tube tapping that portion of the arc-chamber that contains the eaviest gases, and a chamber of enlarged cross-sectional area provided with an outlet of constricted cross-sectional area communicating with the atmosphere.

5. An arc-lamp having an inclosed arcchamber, an elongated attenuated tube tapping that portion of the arc-chamber that contains the heaviest gases, and a member of enlarged cross-sectional area communicating with said tube and with the atmosphere.

6. An arc-lamp having an inclosed arcohamber, an attenuated tube communicating with the interior of the latter, and a member of enlarged cross-sectional area removably secured to and communicating with said tube and open to the atmosphere.

Signed by me this 26th day of July 1905.

BERNARD A. STOWE. 

